Quick-acting thermostat



Dec. 1924- 1,520,499

A. JOHNSON QUICK ACTING THERMOSTAT Filed Nov. 19, 1923 a Jim/61771 011 k 6510a 15 N 33 7m alfarnayg a Patented Dec. 23, 1924.

UNITED STATES PATEIST OFFICE.

AxEL JOHNSON, or oaxnenn cenrronnm.

QUICK-ACTING THERMOSTAT.

Application filed November 19, 1923. Serial No. 675 152.

To all whom it may concern:

Be it known that I, Axnn JOHNSON, a citizen of the United States, residing at Oakland, in the county of Alameda and State of California, have invented certain new and" useful Improvements in Quick Acting Thermostats, of which the followin is a specification.

hermostats as heretofore generally manufactured have beenconstructed to accomplish a relatively slow break between the electrical contact points of the circuit to be controlled, resulting in an arc being formed on the making and breaking of the points which in time causes the pitting of the points and an inefficient completion of .lever may the circuit when the contacts are closed.

The present invention relates to a thermostat designed particularly for controlling electrical circuits whereby in its use a quick breaking and completion of the circuit is made, overcoming the arcing between the contact points and consequently overcoming the burning out and pitting of the contact points. One of the objects of this invention is to provide a thermostat controlling an electric circuit by the use of which. renewal of the contactpoints'is reduced to a minimum; one wherein the contact points are positively retained in opened or closed position when moved thereint-o by the action of the .thermostat, one in which the adjustment of the thermostat can be readily varied and wherein the tension of the means for.

accelerating the movement of the contact e varied. With the above mentioned and other ob- 'jects in view, the invention consists in the novel construction and combination of parts hereinafter described, illustrated in the accompanymg drawings, and-set forth in the claims hereto appended, it being understood that various changes in the form, proportion, size and'minor details of construction within the scope of the claims may be resorted to without departing from the spirit or sacrificing any of the advantages of the invention.

Fig. 1 is a. view in side elevation, of the referred embodiment of my invention illustrating-the parts in a position with the contact finger closed.

Fig. 2 is a view similar to Fig. 1 illustrating the reverse side of the invention and with the contact fingers in open position.

v: Fig. 3 is a view-m front elevation.

Fig. 4 is a View detail in longitudinal section of the trigger movement accelerating means illustrating the plunger in contact with one face of the trigger end incline.

Fig. 5 is a view similar to Fig. 4 illustrating the trigger plunger in contact with the opposite face of the trigger end incline.

Fig. 6 is a transverse sectional view taken on the line 66 of Fig. 1.

In the drawings, wherein like characters of reference indicate corresponding parts throughout the several views, 1 indicates a base preferably of insulating material to.

which is secured the flange portion 2 of a supporting plate 3. The flange 2 of the plate 3 is secured to the base by one or more bolts 4, one of which serves as a binding post for attaching an electric conductor. Secured to the base at a point removed from the plate 3 by a nut 5 is a stationary contact member 6,'the securing nut affording a binding post for the attachment of an electrical conductor. Fulcrumed at one end as at 7 to the plate 3 is a movable contact lever 8 the end 9 of which is adapted for movement into and out of contact with the stationary contact member 6. To operate the lever 8 I employ an element referred to herein as a trigger 10 fulcrumed at one end as at 11 to the plate 3 and the same is provided with a recess 12 into which extends the angularly bent finger portion 13 projecting laterally from one edge of the movable contact lever 8. I provide a free movement between the edges of the recess 12 and the opposite faces of the member 13 which permits of'a movement of the trigger 10 prior to its operating the lever 8. Integral with the trlgger 10 is formed an arm 14 extending preferably parallel with the contact lever 8 and at its endthe same carries an adjustable headed screw member 15 adapted to be received ing one face of the member 13 and the ad-- justment of the apparatus in such that the trigger is preferably in the center of its arcuate movement in either direction prior to imparting any movement to the lever 8. To accelerate the movement of the trig- 'ver- 8, I but 1 ger after the same has been moved .by the thermostat bar 17 a predetermined distance, I employ an accelerating means, the present embodiment of which isillustrated as a reciprocating plunger 19 having a V-shaped lower end 20 which engages the opposite inclined faces of an inverted V-shaped upper end 21 formed on the-trigger 10, this construction being clearly illustrated in 4 and 5. The plunger reciprocates in a tu bular guide .22 and is normally pressed downwardly by a coiled spring 23 surrounding the stem '25 at the upper end of the stem 24 and bearing against the-upper endof the tubular portion 22 is adapted for. varying the operative movement of the plunger-19. A leaf spring 26 having a curved free'end 27 disposed to slightly overlie the'path of movement ofthe free end of the member 8 and secured to the basel as at 27 is adapted for positively maintaining the movable contact lev-er 8 in either open or closed position. I

The parts of the embodiment illustrated *being'assembled as in Fig.1 of the drawings, an increase in temperature suflicient to op 'erate the bar 17, will cause the free end of the bar to swing'and this will impart an outward movement to the trigger 10, cans} ing the wall of the-inverted V-end 21 of'the trigger to ride-over one wall of the V end of the plunger 19 until such time as the tri ger has :icompleted approximately one-ha f ofits arcuate movement. Up to this time movement has not been imparted to the leediately' on the thermostat bar17 mdvin' thetri'ggerlO t o a point be yond-its"med1an-1ine of movement the action ofsthespringi23 on the plunger 19 will cause the plunger to accelerate thepifmove-- ment ofthe trigger which'in turnwill cause arapid movement from making to breakin posltion of the contact lever 8. On'the coolmg of the thermostat bar 17 the movement o'f't'he parts in a reverse direction takes place and the "movable contact lever 8 is rapidly trigger into contact with one edge of the le-' ver 8 and assist in maintaining the lever in contact or circuit closing position.

Having thus described my invention, what I claim as new and desire to protect by Let- 'ters Patent of the United States is 24 thereof. An adjusting nut 1. A thermostatic control for electric circuits including a stationary contact and an associated contact lever adapted for pivotal movement'to and from said stationary contact, a pivotally mounted tri er, a thermostat operatively connected wit the trigger, means c -Operating with the trigger for accelerating its movement in either direction.

after being moved to a predetermined point in said direction by the thermostat, and a loose connection between the lever and trigger whereby accelerated movement is imparted to the tri ger prior to the operation of the lever there i 2. A thermostat ccontrol for electric circuits including a stationary contact and an associated contact lever adapted for pivotal movement to and from said stationary contact, a pivotally mounted trigger and provided' with intersecting bevel ed. faces, a thermostat for operat "said trigger, a spring ressed plunger having intersecting bevelle faces for co-operat ng ,with the bevelled faces of said trigger for imparting accelerated movement to thel'tri ger after the same has been moved a pre etermined distance by said thermostat, and a loose con; nection between the trigger'and lever where by accelerated movement is imparted to the trigger prior to the trigger, operating the lever. In testimony whereof I have.signed my name 'to this specificatio v .AZXEL JOHNSON.

will be observed that the action of the 

